Multi-ply container

ABSTRACT

A multi-ply container of fiberboard material made from three separate four-panel blanks adhesively attached to one another. At three of the four corners there are hinge lines from only two of said blanks, whereas at the remaining corner there is one hinge line from each blank. However, the hinge line at this corner of either the inner or center blank has a central blind slot extending for the major portion of its length, and the hinge line of the other blank has upper and lower short slots at the ends thereof.

o Umted States Patent ml [111 3,744,702 Ellison July 10, 1973 [54] MULTl-PLY CONTAINER 3,559,867 2/l97l Muskopf et al 229/14 R Inventor: Donald E- Euison y 1nd. 3,653,578 4/1972 11/00! 229/23 R [73] Assignee: Inland Container Corporation, p i E iner-D vis T, Moorhead dlanap s, Attorney-William B. Anderson, Robert B. Jones et a1. [22] Filed: Jan. 26, 1972 Y 211 App]. 190.; 220,339 1571 ABSTRACT A multi-ply container of fiberboard material made from three separate four-panel blanks adhesively atg 229/23 tached to one another. At three of the four corners [58] Fie'ld 4 R 4 BL there are hinge lines from only two of said blanks, 229/23 DIG whereas at the remaining corner there is one hinge line from each blank. However, the hinge line at this corner f either the inner or center blank has a central blind [56] References Cited .9

slot extendlng for the ma or portlon of lts length, and UNITED STATES PATENTS the hinge line of the other blank has upper and lower 2,208,268 7/1940 Snyder et al. 229/23 R shQrt slots at the ends thereof 2,734,676 2/1956 Lawrence 229/D1G. 4 3,012,660 12/1961 Sheldom, Jr. 229/23 R X 7 Claims, 10 Drawing Figures MULTI-PLY CONTAINER This application relates generally to containers and more particularly to a reinforced container made from a plurality of fiberboard blanks and to a method for making such a container.

Bulk flowable materials, such as synthetic resins, crudeor synthetic rubber, viscous liquid materials, frozen foods and the like, have a substantial weight per unit volume. In order to utilize fiberboard containers for the shipment of these materials, various specialized containers have been developed, and these containers are often referred to as bulk containers or bulk bins.

Many of these containers utilize more than one ply of corrugated fiberboard, and the construction of such multi-ply containers inherently provides more leeway to tailor a particular container design to a particular need by selection of different weight fiberboard sheets and/or different flute sizes. Better designs of such multi-ply containers are always being sought.

An object of the present invention is to provide an improved multi-ply fiberboard container which is particularly suitable for bulk materials. Another object is to provide a reinforced bulk container which can be inexpensively fabricated of materials particularly suited for aspecific application. A further object is to provide a method for efficiently assembling reinforced containers from a plurality of individual blanks.

These and other objects of the invention should be apparent from the following detailed description of containers embodying various features of the invention when read in conjunction with the accompanying drawings wherein:

FIG. 1 is an exploded perspective view of a container embodying various features of the invention;

FIG. 2 is a horizontal cross sectional view of the container illustrated in FIG. 1 shown in its assembled condition;

FIG. 3 is a plan view of the blank which forms the outer ply of the container shown in FIG. 1;

FIG. 4 is a plan view of the blank which forms the center ply of the container shown in FIG. 1;

FIG. 5 is a plan view of the blank which forms the inner ply of the container shown in FIG. 1;

FIG. 6 is a view of the outer ply blank after the adhesive pattern has been applied in the fabrication process;

FIG. 7 is a view of the blank shown in FIG. 6 having the blank which forms the center ply positioned thereupon and coated with its own adhesive pattern;

FIG. 8 is a view of the blank assembly shown in FIG. 7 with the blank that forms the inner ply positioned thereupon;

FIG. 9 is a view of the blank assembly shown in FIG. 8 with the glue pattern applied to the tab and being folded to begin the formation of the tubular structure; and

FIG. 10 is a view after the folding is completed to establish the manufacturers joint.

Illustrated in the drawings is a bulk container 11 which is made of three separate folded blanks, an outer blank 13, a center blank 15, and an inner blank 17. The configuration of the outer blank 13 is standard having the bottom closure of a regular slotted container (RSC) and a flanged upper end.

More specifically as seen in FIG. 3, the outer blank 13 contains four rectangular panels, viz. side panels 19a and 19b and end panels 21a and 21b, which are hinged together along score lines 23a, 23b and 230. A verticaltab 25, hingedly attached to the side panel 1% along a score line 23d, is providedfor making amanufacturers joint by suitable attachment to the outer surface of the end panel 21a. The joint may be stitched or stapled, or the tab 25 may be omitted and a taped joint used. However, the joint is preferably glued and is so referred to hereinafter. Attached to the sidewalls and end walls along appropriate horizontal score lines are four bottom flaps 27 and four top flanges 29. Although the illustrated container is designed for use with'an interlocking cover (not shown), it should be understood that other types of top closures and/or bottom closures may be substituted. For example, a tray-top cover may be used for a particular application.

Although not specifically illustrated in order to We serve the clarity of the drawings, the fiberboard material from which the outer blank is made is preferably double wall corrugated fiberboard. The center blank 15 and inner blank 17 are also made from corrugated fiberboard, preferably double wall, although single wall or triple wall might be used for a. specific application. The construction of the three-ply container 11 can be precisely tailored to meet the specifications of a particular job because, if desired, each of the three blanks can be made from different corrugated fiberboard material, thus allowing the flute size and the weight of the linerboard to be varied to provide a desired composite fiberboard particularly suited for a specific job.

In containers having three separate plies of corrugated fiberboard material laminated to one another, the accumulation of material at the corners of the fabricated container may make folding difficult and can possibly cause the outermost linerboard of the outer ply to split. This problem is particularly acute at the two corners that are folded at nearly 180 angles when the fabrication of the container is completed by establishing the manufactueres joint and subjecting to compression. Provision is made in the illustrated embodiment to alleviate this problem at both of the corners in question and to facilitate the assembly of the three blanks in the fabrication process.

The blank 15 which forms the center ply includes four panels, viz., side panels 31a and 31b and end panels 33a and 33b, hingedly interconnected by three score lines 35a, 35b and 350. The blank 17 which serves as the inner ply is likewise made up of four panels, viz., side panels 41a and 41b and end panels 43a and 43b which are hinged to one another along three vertical score lines 45a, 45b and 45c. As best seei'i in FIG. 2, the center blank 15 and the inner blank 17 are so positioned and dimensioned that they terminate slightly short of the two diagonally opposite corners that are each folded nearly 180 when the container 1 l is in the knockdown condition, in which it is shipped to the user after fabrication. As viewed in FIG. 2, these two corners appear as the upper righthand corner and the lower lefthand comer. Termination is this fashion eliminates the potential excess material problem and facilitates fabrication of the containers.

It has been found that potential stress at the upper lefthand comer (FIG. 2) from the three fiberboard plies, such as might make squaring the container more difficult in setting it up for use, can be obviated by providing an elongated central blind slot 39 at the score line 350 in the center blank 15 and by providing a pair of complementary short or nick slots 47 at the upper and lower ends of the score line 45a in the outer blank 17. The combination of the central blind slot 39 and the short slots 47 removes sufficient material at this corner of the container 1 l to obviate the problem of an excess of material at this point.

The width of the slots 39 and 47 should be about equal to the thickness of the corrugated board from which the blank is made. For example, the slots may be about /4 inch wide when the blanks and 17 are made from standard doublewall corrugated fiberboard. The central blind slot 39 should be centered, top to bottom of the blank, and should extend for a distance which is a major portion of the vertical height of the blank 15. Preferably, the central blind slot 39 extends for a distance equal to between about 60 and about 95 percent of the height of the center blank 15. The short slots 47 complement the central blind slot 39 and preferably each extends for a distance equal to between about 2 and about 20 percent of the height of the inner blank 17, the center and inner blanks being generally equal in height. Preferably, the sum of the lengths of the two short slots 47 and the central blind slot 39 should equal at least about 90 percent of the height of the center blank 15. The fabrication of bulk containers of such large size is generally done on a manual or semiautomatic basis where there is manual positioning of the three blanks in desired registration with one another. As explained hereinafter, the provision of the short top and bottom slots 47 facilitates the positioning of one blank atop another and aids in the uniformity with which such bulk containers can be fabricated.

The manufacturers joint is provided at the lower righthand corner by securing the tab to the exterior surface of the end panel 21a of the outer blank 13. As a result of the provision of the manufacutrers joint, there is more fiberboard material located at the lower righthand corner than at the two diagonally opposite corners to which reference was previously made. Preferably, when a glued or stitched joint is employed, a central blind slot 49 is provided in the inner blank 17 along the score line 45c. This central blind slot 49 may have the same dimensions as the slot 39 previously described and serves to facilitate setting-up the container, plus obviates possible stress at the manufactueres joint that could conceivably arise through slight misalignment thereat.

Although it is not felt necessary to provide short or nick slots, similar to the slots 47, at the score line 35a in the center blank 15 to complement the blind slot 49, such slots may optionally be provided if desired. In this respect, production expense can be saved using the same blank as the center blank 15 and the inner blank 17 and simply fabricating twice as many. There is normally only a slight difference in the dimensions of the end panels 330 and 43a and the side panels 31b and 41b of these two blanks. The difference is not substantial, and in the illustrated arrangement depicted in FIG. 2, where the same relative panel on the center blank 15 is not laminated to the corresponding panel on the inner blank 17, precision of these dimensions is not too important. In production, the side panel 31a will normally be slightly shorter than the panel 31b and the width of the end panel 33b will normally be slightly less than that of the end panel 33a to provide the illustrated gap in the corners. Because the panel 41b is not laminated to the panel 31b, nor is the panel 43a laminated to the panel 33a, misalignment at corresponding score lines is not a potential problem. Accordingly, the illustrated design permits fabrication from an outer blank 13 and another blank design which can serve as both the inner ply and center ply, thus reducing production costs by having to set up for the manufacture of only two blanks rather than for three.

The fabrication of the laminated container 11 is illustrated in FIGS. 6 through 10 and may be carried out either manually or semiautomatically as machinery to accomplish this method becomes available at a particular plant location. Initially, a suitable adhesive pattern 63 is applied to the interior surface of all four panels of the outer blank 13. The center blank 15 is then positioned atop the adhesive pattern 63. The end panel 33b of the center blank is aligned with the end panel 21b of the outer blank 15. The side panel 31b of the center blank is aligned with the side panel 19a and the end panel 33a is aligned with the end panel 21a of the outer blank. The provision of the blind central slot 39 facilitates the alignment of the center blank atop the outer blank by permitting the operator to sight the score line 23b through the blind slot 39.

With the center blank 15 in proper registration, a similar adhesive pattern 65 is applied to the interior surfaces of all four panels of the center blank 15, as illustrated in FIG. 7.

The inner blank 17 is then folded in half about the score line 45b and is placed as illustrated in FIG. 8 atop the interior surface of the center panel where the adhesive pattern 65 has just been applied. In this respect, the end panel 43a is placed in registration with the end panel 335 of the center blank 15, and the side panel 41a is placed in registration with the side panel 31b. It is in this step that the short slots 47 are of great value in assuring that precise alignment is attained. The provision of the upper and lower slots 47 enables the operator to sight the score line 350 which lies therebeneath to ascertain that the inner blank 17 is correctly positioned.

A glue pattern 67 is then applied to the interior surface of the tab 25, and the final folding is performed as shown in FIGS. 9 and 10. First the folding of the outer and center panels about the score lines 23a and 35b, respectively, is carried out to reach the configuration shown in FIG. 9 wherein the side panel 310 of the center blank is in registration with the side panel 41b of the inner blank. Then the final fold is made about the score line 230 of the outer blank to reach the configuration shown in FIG. 10 wherein the tab 25 is in contact with the outer surface of the panel 21a. Normally, compression will be applied to the three blanks in the configuration shown in FIG. 10 for a sufficient amount of time for the adhesive to set and thereby assure a strong bond throughout the laminations between panels and at the manufacturer's joint.

Other modifications than those enumerated above may be made to the illustrated configuration without departing from the spirit and scope of the invention which is defined by the claims set forth hereinafter.

Various of the features of the invention are set forth in the following claims.

What is claimed is:

l. A multi-ply container of fiberboard material, which container comprises three separate blanks each having four panels connected along vertical hinge lines which blanks are adhesively attached to one another to provide an inner ply, a center ply and an outer ply, said blanks being arranged so that said hinge lines from only two of said blanks are located at each of three of the four corners whereas at the remaining corner there is located one of said hinge lines from each of said three blanks, and the hinge line located at said remaining corner of one of said inner and center blanks having a central blind slot that extends for the major portion of the length of said hinge line and the hinge line of the other of said inner and center blanks having upper and lower short slots that extend inward respectively. from the upper and lower ends of said hinge line.

2. A container in accordance with claim 1 wherein said central blind slot extends for a distance between about 60 and about 95 percent of the length of said hinge line.

3. A container in accordance with claim 2 wherein said short slots each extend for a distance between about 2 and about 20 percent of the length of said hinge line.

4. A container in accordance with claim 1 wherein said outer blank is provided with a tab that forms a manufacturers joint on the exterior surface of said container and wherein the corner of said container where said joint is located is diagonally opposite said remaining corner.

5. A container in accordance with claim 4 wherein said inner blank contains a central blind slot extending for a major portion of the length of the hinge line located at the corner having said manufactueres joint.

'6. A container in accordance with claim 5 wherein said central blind slot at said remaining corner is located on said center blank.

7. A container in accordance with claim 6 wherein the construction of said inner and center blanks is similar, each having a central blind slot along one of said hinge lines and each having upper and lower short slots along another of said hinge lines thereof. 

1. A multi-ply container of fiberboard material, which container comprises three separate blanks each having four panels connected along vertical hinge lines which blanks are adhesively attached to one another to provide an inner ply, a center ply and an outer ply, said blanks being arranged so that said hinge lines from only two of said blanks are located at each of three of the four corners whereas at the remaining corner there is located one of said hinge lines from each of said three blanks, and the hinge line located at said remaining corner of one of said inner and center blanks having a central blind slot that extends for the major portion of the length of said hinge line and the hinge line of the other of said inner and center blanks having upper and lower short slots that extend inWard respectively from the upper and lower ends of said hinge line.
 2. A container in accordance with claim 1 wherein said central blind slot extends for a distance between about 60 and about 95 percent of the length of said hinge line.
 3. A container in accordance with claim 2 wherein said short slots each extend for a distance between about 2 and about 20 percent of the length of said hinge line.
 4. A container in accordance with claim 1 wherein said outer blank is provided with a tab that forms a manufacturer''s joint on the exterior surface of said container and wherein the corner of said container where said joint is located is diagonally opposite said remaining corner.
 5. A container in accordance with claim 4 wherein said inner blank contains a central blind slot extending for a major portion of the length of the hinge line located at the corner having said manufacturer''s joint.
 6. A container in accordance with claim 5 wherein said central blind slot at said remaining corner is located on said center blank.
 7. A container in accordance with claim 6 wherein the construction of said inner and center blanks is similar, each having a central blind slot along one of said hinge lines and each having upper and lower short slots along another of said hinge lines thereof. 